Unit 3 - Life On Earth Flashcards
What is meant by the term abiotic factor?
Non-living things.
What is meant by the term biotic factor?
Living things.
Give examples of abiotic factors:
- Light Intensity
- pH
- Temperature
- Moisture level
Give examples of biotic factors:
- Disease
- Predators
- Food
- Grazing
What is meant by the term biome?
The geographical area of the planet that contains distinctive communities of fauna (animals) and flora (plants).
What is meant by the term Niche?
A role than an organism that plays within a community.
What is meant by the term habitat?
The place where the organism lives.
What is meant by the term Population?
The total number of one species.
What is meant by the term community?
All the population of plants and animals in an ecosystem.
What is meant by the term ecosystem?
All the community of living things and their habitat.
What is meant by the term biodiversity?
A total variety of all living things on earth.
What does a pyramid of biomass show?
A pyramid of biomass shows the total mass of organism at each level in the food chain.
What does a pyramid of numbers show?
The pyramid of number shows the total number of organisms.
What does a pyramid of energy show?
A pyramid of energy shows the total energy at each level.
What do organism need nitrogen for?
To make proteins.
What are the four different types of bacteria and what are their functions?
•Nitrogen fixing bacteria -converts nitrogen gas to nitrate. •Decomposers (bacteria and fungus) -convert pro town to ammonium compounds. •Nitrifying bacteria -some covert ammonium compounds to nitrate and some concert nitrite to nitrate. •Denitrifying bacteria -covert useful nitrate to nitrogen gas
What are nitrification and denitrification carried out by?
Decomposers
What do Decomposers (bacteria/fungus) use as an energy source?
They use dead plants and animals as an energy source.
What is meant by the term intraspecific competition?
Intraspecific competition occurs when the individuals of the same species compete for exactly the same resources.
What is meant by the term interspecific competition?
Interspecific competition occurs when the individuals of the different species compete for exactly the same resources.
What is meant by the term adaptation?
An adaptation is a characteristic possessed by an organism which make it well suited to its environment.
What is meant by the term natural selection?
Natural selection is a process where organisms which are better adapted to their environment survive and breed. These organisms which are less well adapted doe before they reproduce.
What is meant by the term indicator species?
An organism whose presence or ensemble can be used to show the levels of pollution in the environment.
What is meant by the term biological control?
Biological control is an alternative to using pesticides that can be harmful to the environment.
What is meant by the term GM Crops?
Genetically modified crops is crops that have had their genetic information (DNA) changed to improve their characteristics.
What is meant by the term bioaccumulation?
Bioaccumulation means when harmful chemicals can enter the food chain and their level can rise.
How are new species formed?
Initial population is separated. Different mutation occurs at am each Subpopulation. Natural selection occurs. Subpopulation are no longer able to interbreed to produce a fertile offspring.
